Midway sells Norma 45-120 brass in bulk for about $1.48 each.

They will back order a box of Bertram 450#2 brass for $110.00 if you so desire.

I have a 450#2 Jeffery and have both Bertram and Horny-berner. The rim on the Bertram brass tends to be too thick on some.

The modern brass for 45-120 is plenty strong for modern firearms.

84 grains of R15 a foam wad and topped off with a 480 grain Woodleigh is all you need.